1. Field of the Invention
The present invention relates to a legged mobile robot using leg portions, a legged mobile robot controller for controlling the legged mobile robot, and a legged mobile robot controlling method.
2. Description of the Related Art
There have been known legged mobile robots walking or running (hereinafter referred to as “moving”) by legs. Such robots usually have a human-like figure with a head, arm portions, a body and leg portions, thereby encouraging natural communication with humans.
Robots, specifically industrial robots, usually assemble components, grip an object and transfer a product, or the like.
Those industrial robots are generally constituted merely of arm portions for assembling components or for grasping an object (often referred to as a “robot hand” or “robot arm”)
Such a “robot hand” as disclosed in JP2004-160594A is designed so as to determine a grasp motion by calculating an approximate figure of an object to be grasped, based on a touch sensor, an open angle sensor or the like.
In addition, such a “robot grip controller” as disclosed in JP2004-167674A is designed to detect on an external force sensor a value of an external force affecting a robot hand that grips an object, and increase or decrease a grip force of the robot hand to grip the object in accordance with changes of the external value, thereby receiving and handing out the object.
If a legged mobile robot is provided with those well-known robot hands or a grip controller so as to grip an object and load the object on an appropriate place under an autonomous control with no operator's control, the legged mobile robot cannot keep the object in parallel and tilt it, resulting in losing a balance in keeping the posture thereof.
In particular, there have been a disadvantage that, if the legged mobile robot grips the object with the arms thereof and loads the gripped object on the appropriate place (e.g. on a table with a predetermined height), a height of the appropriate place on which the object is loaded is limited within a stretchable range of the robot's arms, compared to a conventional robot arm.
The present invention has an object to provide a legged mobile robot controller, a legged mobile robot and the legged mobile robot control method, which make it possible to load a gripped object on a target place having a height where a stretchable range of the arms is enhanced, while maintaining the posture of the legged mobile robot in accordance with a predetermined posture with no operator's handling, thereby solving the above disadvantage.